Re: [PATCH v5 2/2] thermal: add brcmstb AVS TMON driver

[Markus Mayer]

On 26 September 2017 at 14:32, Scott Branden <scott.branden@xxxxxxxxxxxx> wrote:
> Hi Markus,
>
>
> On 17-09-26 02:27 PM, Markus Mayer wrote:
>>
>> From: Brian Norris <computersforpeace@xxxxxxxxx>
>>
>> The AVS TMON core provides temperature readings, a pair of configurable
>> high- and low-temperature threshold interrupts, and an emergency
>> over-temperature chip reset. The driver utilizes the first two to
>> provide temperature readings and high-temperature notifications to
>> applications. The over-temperature reset is not exposed to
>> applications; this reset threshold is critical to the system and should
>> be set with care within the bootloader.
>>
>> Applications may choose to utilize the notification mechanism, the
>> temperature reading mechanism (e.g., through polling), or both.
>>
>> Signed-off-by: Brian Norris <computersforpeace@xxxxxxxxx>
>> Signed-off-by: Doug Berger <opendmb@xxxxxxxxx>
>> Signed-off-by: Markus Mayer <mmayer@xxxxxxxxxxxx>
>> ---
>>   drivers/thermal/Kconfig                    |   2 +-
>>   drivers/thermal/broadcom/Kconfig           |   7 +
>>   drivers/thermal/broadcom/Makefile          |   1 +
>>   drivers/thermal/broadcom/brcmstb_thermal.c | 387
>> +++++++++++++++++++++++++++++
>>   4 files changed, 396 insertions(+), 1 deletion(-)
>>   create mode 100644 drivers/thermal/broadcom/brcmstb_thermal.c
>>
>> diff --git a/drivers/thermal/Kconfig b/drivers/thermal/Kconfig
>> index 07002df..96774a7 100644
>> --- a/drivers/thermal/Kconfig
>> +++ b/drivers/thermal/Kconfig
>> @@ -408,7 +408,7 @@ config MTK_THERMAL
>>           controller present in Mediatek SoCs
>>     menu "Broadcom thermal drivers"
>> -depends on ARCH_BCM || COMPILE_TEST
>> +depends on ARCH_BCM || ARCH_BRCMSTB || COMPILE_TEST
>
> No need for this additional depends.  ARCH_BCM is always defined before
> ARCH_BRCMSTB can be selected.

ARCH_BCM does not exist in arch/arm64/configs/defconfig. ARCH_BRCMSTB
does. So, we do need both or the driver won't be built on ARM64.
(After internal discussions we went with that approach rather than
defining ARCH_BCM on ARM64.)

>>   source "drivers/thermal/broadcom/Kconfig"
>>   endmenu
>>   diff --git a/drivers/thermal/broadcom/Kconfig
>> b/drivers/thermal/broadcom/Kconfig
>> index 42c098e..c106a15 100644
>> --- a/drivers/thermal/broadcom/Kconfig
>> +++ b/drivers/thermal/broadcom/Kconfig
>> @@ -6,6 +6,13 @@ config BCM2835_THERMAL
>>         help
>>           Support for thermal sensors on Broadcom bcm2835 SoCs.
>>   +config BRCMSTB_THERMAL
>> +       tristate "Broadcom STB AVS TMON thermal driver"
>> +       depends on ARCH_BRCMSTB || COMPILE_TEST
>> +       help
>> +         Enable this driver if you have a Broadcom STB SoC and would like
>> +         thermal framework support.
>> +
>>   config BCM_NS_THERMAL
>>         tristate "Northstar thermal driver"
>>         depends on ARCH_BCM_IPROC || COMPILE_TEST
>> diff --git a/drivers/thermal/broadcom/Makefile
>> b/drivers/thermal/broadcom/Makefile
>> index c6f62e4..fae10ec 100644
>> --- a/drivers/thermal/broadcom/Makefile
>> +++ b/drivers/thermal/broadcom/Makefile
>> @@ -1,2 +1,3 @@
>>   obj-$(CONFIG_BCM2835_THERMAL)         += bcm2835_thermal.o
>> +obj-$(CONFIG_BRCMSTB_THERMAL)          += brcmstb_thermal.o
>>   obj-$(CONFIG_BCM_NS_THERMAL)          += ns-thermal.o
>> diff --git a/drivers/thermal/broadcom/brcmstb_thermal.c
>> b/drivers/thermal/broadcom/brcmstb_thermal.c
>> new file mode 100644
>> index 0000000..1919f91
>> --- /dev/null
>> +++ b/drivers/thermal/broadcom/brcmstb_thermal.c
>> @@ -0,0 +1,387 @@
>>
>> +/*
>> + * Broadcom STB AVS TMON thermal sensor driver
>> + *
>> + * Copyright (c) 2015-2017 Broadcom
>> + *
>> + * This software is licensed under the terms of the GNU General Public
>> + * License version 2, as published by the Free Software Foundation, and
>> + * may be copied, distributed, and modified under those terms.
>> + *
>> + * This program is distributed in the hope that it will be useful,
>> + * but WITHOUT ANY WARRANTY; without even the implied warranty of
>> + * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
>> + * GNU General Public License for more details.
>> + *
>> + */
>> +
>> +#define DRV_NAME       "brcmstb_thermal"
>> +
>> +#define pr_fmt(fmt)    DRV_NAME ": " fmt
>> +
>> +#include <linux/bitops.h>
>> +#include <linux/device.h>
>> +#include <linux/err.h>
>> +#include <linux/io.h>
>> +#include <linux/irqreturn.h>
>> +#include <linux/interrupt.h>
>> +#include <linux/kernel.h>
>> +#include <linux/module.h>
>> +#include <linux/platform_device.h>
>> +#include <linux/of_device.h>
>> +#include <linux/thermal.h>
>> +
>> +#define AVS_TMON_STATUS                        0x00
>> + #define AVS_TMON_STATUS_valid_msk     BIT(11)
>> + #define AVS_TMON_STATUS_data_msk      GENMASK(10, 1)
>> + #define AVS_TMON_STATUS_data_shift    1
>> +
>> +#define AVS_TMON_EN_OVERTEMP_RESET     0x04
>> + #define AVS_TMON_EN_OVERTEMP_RESET_msk        BIT(0)
>> +
>> +#define AVS_TMON_RESET_THRESH          0x08
>> + #define AVS_TMON_RESET_THRESH_msk     GENMASK(10, 1)
>> + #define AVS_TMON_RESET_THRESH_shift   1
>> +
>> +#define AVS_TMON_INT_IDLE_TIME         0x10
>> +
>> +#define AVS_TMON_EN_TEMP_INT_SRCS      0x14
>> + #define AVS_TMON_EN_TEMP_INT_SRCS_high        BIT(1)
>> + #define AVS_TMON_EN_TEMP_INT_SRCS_low BIT(0)
>> +
>> +#define AVS_TMON_INT_THRESH            0x18
>> + #define AVS_TMON_INT_THRESH_high_msk  GENMASK(26, 17)
>> + #define AVS_TMON_INT_THRESH_high_shift        17
>> + #define AVS_TMON_INT_THRESH_low_msk   GENMASK(10, 1)
>> + #define AVS_TMON_INT_THRESH_low_shift 1
>> +
>> +#define AVS_TMON_TEMP_INT_CODE         0x1c
>> +#define AVS_TMON_TP_TEST_ENABLE                0x20
>> +
>> +/* Default coefficients */
>> +#define AVS_TMON_TEMP_SLOPE            -487
>> +#define AVS_TMON_TEMP_OFFSET           410040
>> +
>> +/* HW related temperature constants */
>> +#define AVS_TMON_TEMP_MAX              0x3ff
>> +#define AVS_TMON_TEMP_MIN              -88161
>> +#define AVS_TMON_TEMP_MASK             AVS_TMON_TEMP_MAX
>> +
>> +enum avs_tmon_trip_type {
>> +       TMON_TRIP_TYPE_LOW = 0,
>> +       TMON_TRIP_TYPE_HIGH,
>> +       TMON_TRIP_TYPE_RESET,
>> +       TMON_TRIP_TYPE_MAX,
>> +};
>> +
>> +struct avs_tmon_trip {
>> +       /* HW bit to enable the trip */
>> +       u32 enable_offs;
>> +       u32 enable_mask;
>> +
>> +       /* HW field to read the trip temperature */
>> +       u32 reg_offs;
>> +       u32 reg_msk;
>> +       int reg_shift;
>> +};
>> +
>> +static struct avs_tmon_trip avs_tmon_trips[] = {
>> +       /* Trips when temperature is below threshold */
>> +       [TMON_TRIP_TYPE_LOW] = {
>> +               .enable_offs    = AVS_TMON_EN_TEMP_INT_SRCS,
>> +               .enable_mask    = AVS_TMON_EN_TEMP_INT_SRCS_low,
>> +               .reg_offs       = AVS_TMON_INT_THRESH,
>> +               .reg_msk        = AVS_TMON_INT_THRESH_low_msk,
>> +               .reg_shift      = AVS_TMON_INT_THRESH_low_shift,
>> +       },
>> +       /* Trips when temperature is above threshold */
>> +       [TMON_TRIP_TYPE_HIGH] = {
>> +               .enable_offs    = AVS_TMON_EN_TEMP_INT_SRCS,
>> +               .enable_mask    = AVS_TMON_EN_TEMP_INT_SRCS_high,
>> +               .reg_offs       = AVS_TMON_INT_THRESH,
>> +               .reg_msk        = AVS_TMON_INT_THRESH_high_msk,
>> +               .reg_shift      = AVS_TMON_INT_THRESH_high_shift,
>> +       },
>> +       /* Automatically resets chip when above threshold */
>> +       [TMON_TRIP_TYPE_RESET] = {
>> +               .enable_offs    = AVS_TMON_EN_OVERTEMP_RESET,
>> +               .enable_mask    = AVS_TMON_EN_OVERTEMP_RESET_msk,
>> +               .reg_offs       = AVS_TMON_RESET_THRESH,
>> +               .reg_msk        = AVS_TMON_RESET_THRESH_msk,
>> +               .reg_shift      = AVS_TMON_RESET_THRESH_shift,
>> +       },
>> +};
>> +
>> +struct brcmstb_thermal_priv {
>> +       void __iomem *tmon_base;
>> +       struct device *dev;
>> +       struct thermal_zone_device *thermal;
>> +};
>> +
>> +static void avs_tmon_get_coeffs(struct thermal_zone_device *tz, int
>> *slope,
>> +                               int *offset)
>> +{
>> +       *slope = thermal_zone_get_slope(tz);
>> +       *offset = thermal_zone_get_offset(tz);
>> +}
>> +
>> +/* Convert a HW code to a temperature reading (millidegree celsius) */
>> +static inline int avs_tmon_code_to_temp(struct thermal_zone_device *tz,
>> +                                       u32 code)
>> +{
>> +       const int val = code & AVS_TMON_TEMP_MASK;
>> +       int slope, offset;
>> +
>> +       avs_tmon_get_coeffs(tz, &slope, &offset);
>> +
>> +       return slope * val + offset;
>> +}
>> +
>> +/*
>> + * Convert a temperature value (millidegree celsius) to a HW code
>> + *
>> + * @temp: temperature to convert
>> + * @low: if true, round toward the low side
>> + */
>> +static inline u32 avs_tmon_temp_to_code(struct thermal_zone_device *tz,
>> +                                       int temp, bool low)
>> +{
>> +       int slope, offset;
>> +
>> +       if (temp < AVS_TMON_TEMP_MIN)
>> +               return AVS_TMON_TEMP_MAX; /* Maximum code value */
>> +
>> +       avs_tmon_get_coeffs(tz, &slope, &offset);
>> +
>> +       if (temp >= offset)
>> +               return 0;       /* Minimum code value */
>> +
>> +       if (low)
>> +               return (u32)(DIV_ROUND_UP(offset - temp, abs(slope)));
>> +       else
>> +               return (u32)((offset - temp) / abs(slope));
>> +}
>> +
>> +static int brcmstb_get_temp(void *data, int *temp)
>> +{
>> +       struct brcmstb_thermal_priv *priv = data;
>> +       u32 val;
>> +       long t;
>> +
>> +       val = __raw_readl(priv->tmon_base + AVS_TMON_STATUS);
>> +
>> +       if (!(val & AVS_TMON_STATUS_valid_msk)) {
>> +               dev_err(priv->dev, "reading not valid\n");
>> +               return -EIO;
>> +       }
>> +
>> +       val = (val & AVS_TMON_STATUS_data_msk) >>
>> AVS_TMON_STATUS_data_shift;
>> +
>> +       t = avs_tmon_code_to_temp(priv->thermal, val);
>> +       if (t < 0)
>> +               *temp = 0;
>> +       else
>> +               *temp = t;
>> +
>> +       return 0;
>> +}
>> +
>> +static void avs_tmon_trip_enable(struct brcmstb_thermal_priv *priv,
>> +                                enum avs_tmon_trip_type type, int en)
>> +{
>> +       struct avs_tmon_trip *trip = &avs_tmon_trips[type];
>> +       u32 val = __raw_readl(priv->tmon_base + trip->enable_offs);
>> +
>> +       dev_dbg(priv->dev, "%sable trip, type %d\n", en ? "en" : "dis",
>> type);
>> +
>> +       if (en)
>> +               val |= trip->enable_mask;
>> +       else
>> +               val &= ~trip->enable_mask;
>> +
>> +       __raw_writel(val, priv->tmon_base + trip->enable_offs);
>> +}
>> +
>> +static int avs_tmon_get_trip_temp(struct brcmstb_thermal_priv *priv,
>> +                                 enum avs_tmon_trip_type type)
>> +{
>> +       struct avs_tmon_trip *trip = &avs_tmon_trips[type];
>> +       u32 val = __raw_readl(priv->tmon_base + trip->reg_offs);
>> +
>> +       val &= trip->reg_msk;
>> +       val >>= trip->reg_shift;
>> +
>> +       return avs_tmon_code_to_temp(priv->thermal, val);
>> +}
>> +
>> +static void avs_tmon_set_trip_temp(struct brcmstb_thermal_priv *priv,
>> +                                  enum avs_tmon_trip_type type,
>> +                                  int temp)
>> +{
>> +       struct avs_tmon_trip *trip = &avs_tmon_trips[type];
>> +       u32 val, orig;
>> +
>> +       dev_dbg(priv->dev, "set temp %d to %d\n", type, temp);
>> +
>> +       /* round toward low temp for the low interrupt */
>> +       val = avs_tmon_temp_to_code(priv->thermal, temp,
>> +                                   type == TMON_TRIP_TYPE_LOW);
>> +
>> +       val <<= trip->reg_shift;
>> +       val &= trip->reg_msk;
>> +
>> +       orig = __raw_readl(priv->tmon_base + trip->reg_offs);
>> +       orig &= ~trip->reg_msk;
>> +       orig |= val;
>> +       __raw_writel(orig, priv->tmon_base + trip->reg_offs);
>> +}
>> +
>> +static int avs_tmon_get_intr_temp(struct brcmstb_thermal_priv *priv)
>> +{
>> +       u32 val;
>> +
>> +       val = __raw_readl(priv->tmon_base + AVS_TMON_TEMP_INT_CODE);
>> +       return avs_tmon_code_to_temp(priv->thermal, val);
>> +}
>> +
>> +static irqreturn_t brcmstb_tmon_irq_thread(int irq, void *data)
>> +{
>> +       struct brcmstb_thermal_priv *priv = data;
>> +       int low, high, intr;
>> +
>> +       low = avs_tmon_get_trip_temp(priv, TMON_TRIP_TYPE_LOW);
>> +       high = avs_tmon_get_trip_temp(priv, TMON_TRIP_TYPE_HIGH);
>> +       intr = avs_tmon_get_intr_temp(priv);
>> +
>> +       dev_dbg(priv->dev, "low/intr/high: %d/%d/%d\n",
>> +                       low, intr, high);
>> +
>> +       /* Disable high-temp until next threshold shift */
>> +       if (intr >= high)
>> +               avs_tmon_trip_enable(priv, TMON_TRIP_TYPE_HIGH, 0);
>> +       /* Disable low-temp until next threshold shift */
>> +       if (intr <= low)
>> +               avs_tmon_trip_enable(priv, TMON_TRIP_TYPE_LOW, 0);
>> +
>> +       /*
>> +        * Notify using the interrupt temperature, in case the temperature
>> +        * changes before it can next be read out
>> +        */
>> +       thermal_zone_device_update(priv->thermal, intr);
>> +
>> +       return IRQ_HANDLED;
>> +}
>> +
>> +static int brcmstb_set_trips(void *data, int low, int high)
>> +{
>> +       struct brcmstb_thermal_priv *priv = data;
>> +
>> +       dev_dbg(priv->dev, "set trips %d <--> %d\n", low, high);
>> +
>> +       /*
>> +        * Disable low-temp if "low" is too small. As per thermal
>> framework
>> +        * API, we use -INT_MAX rather than INT_MIN.
>> +        */
>> +       if (low <= -INT_MAX) {
>> +               avs_tmon_trip_enable(priv, TMON_TRIP_TYPE_LOW, 0);
>> +       } else {
>> +               avs_tmon_set_trip_temp(priv, TMON_TRIP_TYPE_LOW, low);
>> +               avs_tmon_trip_enable(priv, TMON_TRIP_TYPE_LOW, 1);
>> +       }
>> +
>> +       /* Disable high-temp if "high" is too big. */
>> +       if (high == INT_MAX) {
>> +               avs_tmon_trip_enable(priv, TMON_TRIP_TYPE_HIGH, 0);
>> +       } else {
>> +               avs_tmon_set_trip_temp(priv, TMON_TRIP_TYPE_HIGH, high);
>> +               avs_tmon_trip_enable(priv, TMON_TRIP_TYPE_HIGH, 1);
>> +       }
>> +
>> +       return 0;
>> +}
>> +
>> +static struct thermal_zone_of_device_ops of_ops = {
>> +       .get_temp       = brcmstb_get_temp,
>> +       .set_trips      = brcmstb_set_trips,
>> +};
>> +
>> +static const struct of_device_id brcmstb_thermal_id_table[] = {
>> +       { .compatible = "brcm,avs-tmon" },
>> +       {},
>> +};
>> +MODULE_DEVICE_TABLE(of, brcmstb_thermal_id_table);
>> +
>> +static int brcmstb_thermal_probe(struct platform_device *pdev)
>> +{
>> +       struct thermal_zone_device *thermal;
>> +       struct brcmstb_thermal_priv *priv;
>> +       struct resource *res;
>> +       int irq, ret;
>> +
>> +       priv = devm_kzalloc(&pdev->dev, sizeof(*priv), GFP_KERNEL);
>> +       if (!priv)
>> +               return -ENOMEM;
>> +
>> +       res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
>> +       priv->tmon_base = devm_ioremap_resource(&pdev->dev, res);
>> +       if (IS_ERR(priv->tmon_base))
>> +               return PTR_ERR(priv->tmon_base);
>> +
>> +       priv->dev = &pdev->dev;
>> +       platform_set_drvdata(pdev, priv);
>> +
>> +       thermal = thermal_zone_of_sensor_register(&pdev->dev, 0, priv,
>> &of_ops);
>> +       if (IS_ERR(thermal)) {
>> +               ret = PTR_ERR(thermal);
>> +               dev_err(&pdev->dev, "could not register sensor: %d\n",
>> ret);
>> +               return ret;
>> +       }
>> +
>> +       priv->thermal = thermal;
>> +
>> +       irq = platform_get_irq(pdev, 0);
>> +       if (irq < 0) {
>> +               dev_err(&pdev->dev, "could not get IRQ\n");
>> +               ret = irq;
>> +               goto err;
>> +       }
>> +       ret = devm_request_threaded_irq(&pdev->dev, irq, NULL,
>> +                                       brcmstb_tmon_irq_thread,
>> IRQF_ONESHOT,
>> +                                       DRV_NAME, priv);
>> +       if (ret < 0) {
>> +               dev_err(&pdev->dev, "could not request IRQ: %d\n", ret);
>> +               goto err;
>> +       }
>> +
>> +       dev_info(&pdev->dev, "registered AVS TMON of-sensor driver\n");
>> +
>> +       return 0;
>> +
>> +err:
>> +       thermal_zone_of_sensor_unregister(&pdev->dev, thermal);
>> +       return ret;
>> +}
>> +
>> +static int brcmstb_thermal_exit(struct platform_device *pdev)
>> +{
>> +       struct brcmstb_thermal_priv *priv = platform_get_drvdata(pdev);
>> +       struct thermal_zone_device *thermal = priv->thermal;
>> +
>> +       if (thermal)
>> +               thermal_zone_of_sensor_unregister(&pdev->dev,
>> priv->thermal);
>> +
>> +       return 0;
>> +}
>> +
>> +static struct platform_driver brcmstb_thermal_driver = {
>> +       .probe = brcmstb_thermal_probe,
>> +       .remove = brcmstb_thermal_exit,
>> +       .driver = {
>> +               .name = DRV_NAME,
>> +               .of_match_table = brcmstb_thermal_id_table,
>> +       },
>> +};
>> +module_platform_driver(brcmstb_thermal_driver);
>> +
>> +MODULE_LICENSE("GPL v2");
>> +MODULE_AUTHOR("Brian Norris");
>> +MODULE_DESCRIPTION("Broadcom STB AVS TMON thermal driver");
>
>